In an isolated communication system where both analog and digital signals are transmitted across an isolation barrier, two isolation channels are typically required to transmit the two different types of signals across the barrier. Such an isolated communication system is shown in FIG. 1, where input analog signal 10 in isolated communication system 5 is transmitted by transmitter 12 across analog isolator 14 for reception by receiver 16, which in turn generates output analog signal 18, and where input digital signal 20 is transmitted by transmitter 22 across digital isolator 24 for reception by receiver 26, which in turn generates output digital signal 28. The requirement for two different types of isolators in such a system 5 adds to cost. Furthermore, in some cases it is not feasible to employ two isolators in an integrated circuit package due to space constraints.
What is need is an isolated communication system where analog and digital signals can be transmitted and received through a single isolation channel.